Standing seam roof assemblies have been utilized for simpler manufacturing, particularly in order to reduce complexity in erecting buildings. In such assemblies, numerous panels are supplied with differing end portions, each having what is termed a female portion and a smaller male portion. In such a manner, the panels are laid one next to the other and secured through seaming the male and female portions of adjacent panels together. Such roof assemblies are designed to provide excellent watertight seals as well as effective wind resistance to ensure leak-proof structures as well as high stability against updrafts. Additionally, the seams include panel portions that are allowed to flex to compensate for temperature variations so the roof itself will not disintegrate upon contraction or protraction. For simplification of the overall assembly system, the seamed panels are attached to the building structure via brackets or like components, at a limited number of points in each connected panel. Thus, it is very important to provide excellent seal strengths upon seaming of such individual roof assembly panels together in order ensure the roof assembly does not destabilize at the seam attachment points.
The panels themselves are made generally from metal materials that exhibit excellent strength characteristics, low propensity for rusting, and, of great importance, suitable flexibility for seaming to be accomplished. The seam between the two panels provides not only waterproof seals between panels, but also the ability to hold the two panels together effectively to prevent or at least substantially reduce any slippage between them, as alluded to above. Any appreciable reduction in the dimensional stability of the roof assembly itself would result in roof failure from a leakage perspective, at least.
The seam itself should exhibit the highest shear strength to reduce slipping between the panels; it is thus important to provide the strongest joint seal possible, with the lowest degree of manufacturing complexity and the highest level of safety for the builder as well. In the past, the female portion of each panel was produced with an extra hook that permitted an extra joint to be created over the outer edge of the male portion of the adjacent panel. Such a hook thus provided a more robust seal to be attained at the seam after suitable pressure was applied over the entire panel. It has been measured that a seam including such a hook portion can increase the strength of the seam by at least 50% over a non-hook design at a five foot purlin spacing; at a 2½ foot purlin spacing, the increase is even more dramatic, about 75%. Thus, the inclusion of such a hook within the female portion of a panel to be seamed to a male portion of an adjacent panel provides excellent shear strength properties, according even greater reliability as a leak-proof and wind-proof roof assembly. Unfortunately, the typical hook design (wherein the panels are provided with such a hook on the edge of a female portion prior to transport to a building site and placement on a target edifice) has created some noticeable problems that have yet to be overcome.
Such roof assemblies require intensive manpower to first lift and place the panels as needed, and further to initialize the sealing procedure. At a roof height of at least 12 feet, it is imperative for safety purposes to facilitate such roof assembly procedures through simplifying the procedure and best ensuring that cumbersome lifting movements are reduced. With previously produced panels including hook designs within the female portions thereof, instead of a simple placement of the target panels over one another and subsequently seaming such, it has been necessary to actually lift each panel in succession and make sure the hooked female portions actually engage the smaller male portions prior to seaming through a roll-lock procedure. In such a manner, safety precautions must be undertaken to permit such labor intensive actions. The panels themselves are generally quite heavy and mere placement aids in reducing the strain and possible safety compromises that are readily present when the typical pre-hooked panels are utilized. As such, there exists a definite need to provide a simpler, yet just as reliable, manner of seaming standing roof assembly panels.
A need has thus long been recognized for providing such high strength roof assemblies but without the potential dangerous and labor intensive lifting of panels due to the pre-hooked designs used therein. Such pre-hooked panels are generally produced at a panel production plant, rather than on-site at the building location. However, even were such panels produced on-site, the same issues with lifting rather than placing of the panels would be an issue. A manner of actually creating a hook to be integrated within a panel after placing in the target roof location is thus a desired outcome. To date, unfortunately, such a result has not been accorded the metal roofing industry.